Almost any stain we acquire on our teeth from everyday foods, drinks and habits can can be made lighter, whiter and better with the use of professional whitening. I think that this myth was thrown out of perspective, but has some underlying truth to it.
First truth: The longer our teeth come in contact with dark staining foods and drinks, the more susceptible we are to stain. This is why straws can be a good option to lessen the amount of time a dark staining liquid (coffee or soda for example) has in contact with your teeth.
Second truth: After whitening (bleaching), teeth become dehydrated temporarily, making them more susceptible to picking up stain. That's why we advise patients to avoid dark staining things (tobacco, coffee, red wine, etc) for the first 24-48 hours. It's not that your teeth will all of a sudden become a deep Argentinian Malbec Red if you accidentally have a glass of Malbec, it's just more likely that the the whitening you just did won't appear as effective thereby negating the effort you just put in. No worries, you'll just have to bleach an extra night or two to counter that and achieve the whiteness you desire.